This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Natural resources, such as oil and gas, are used as fuel to power vehicles, heat homes, and generate electricity, in addition to a myriad of other uses. Once a desired resource is discovered below the surface of the earth, drilling and production systems are often employed to access and extract the resource. These systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems generally include a wellhead assembly through which the resource is extracted. These wellhead assemblies may include a wide variety of components and/or conduits, such as casings, trees, manifolds, and the like, that facilitate drilling and/or extraction operations.
In some instances, well intervention, or any work involving maintenance, modification, repair, or completion of the well, may be performed by first killing the well and then removing pressure control equipment to enable pipes and/or tools to be lowered into the well. Well kill involves adding heavy fluid to a wellbore to provide hydrostatic pressure, thereby preventing the flow of reservoir fluids from the well. The heavy fluid provides enough pressure to overcome the pressure of the reservoir fluids such that pressure control equipment may be removed from the wellhead assembly to enable completion of the desired intervention. The heavy fluid introduced into the wellbore may impair the resumption of fluid flow after completion of the well intervention. Accordingly, in order to resume production after killing the well, the added heavy fluid is removed from the wellbore.
As an alternative to killing the well to enable intervention work, a technique known as snubbing may be employed while the well is under pressure. In snubbing, a plug is inserted into the well, for example, in the tubing spool. Pressure is thereby isolated upstream of the plug (e.g., between the plug and a mineral deposit, or below the plug), and repairs or modifications may be made to well components downstream of the plug (e.g., between the plug and a riser, or above the plug). When the well intervention is complete, the snubbing plug may be removed and well operations may proceed as usual.